The invention relates to an aircraft passenger seat formed of a mounting frame containing a tilt axis about which a seat part having a seating surface and a backrest is tiltable.
One such aircraft passenger seat is known from German Patent DE 42 22 222 C2. In this known aircraft passenger seat a seat part is configured as a plastic seat shell. In a region of a front edge, the seat part is mounted on a tilt axis fixedly disposed on a mounting frame. Provided at a rear end of the seating surface is a positioner cooperating with a positioning device of the mounting frame to permit setting the tilt of the seat part relative to the mounting frame. Since the seat part is mounted in the region of its front edge, the front edge of the seating surface retains its height at all tilt settings. Although the seating comfort is not detrimented by increased thigh strain, the disadvantage in this known seat is, however, that the passenger is unable to promote the uprighting of the seat part from its lowest position, thus making a relatively complicated lifting device necessary.
It is accordingly an object of the invention to provide an aircraft passenger seat that overcomes the above-mentioned disadvantages of the prior art devices of this general type, in which the uprighting of the seat is promoted by the passenger while minimizing the pressure exerted on the thighs of the passenger.
With the foregoing and other objects in view there is provided, in accordance with the invention, an aircraft passenger seat, including:
a seat part having a middle portion, a backrest and a seating surface with a front portion;
a mounting frame having a tilt axis about which the seat part is tiltable, the tilt axis runs through the middle portion of the seating surface; and
a device disposed on the front portion of the seating surface for reducing a thigh pressure from the front portion of the seating surface on reclining the seat part.
To achieve the object it is proposed in the aircraft passenger seat of the aforementioned kind to dispose the tilt axis in a middle portion of the seating surface and that a device is provided in the front portion of the seating surface which reduces the thigh pressure in the front portion of the seating surface on reclining the seat part.
Since the tilt axis in the aircraft passenger seat in accordance with the invention is disposed in a middle portion, uprighting the seat part from its lowest position is promoted by the passenger. In this configuration the front portion of the seat acts as a lever which promotes uprighting. Although no stationary conditions exist in the front portion of the seating surface, thigh pressure is minimized by the device provided so that seating comfort is not detrimented. The aircraft passenger seat in accordance with the invention contains in all a simple and thus cost-effective structure.
Advantageously, the tilt axis is disposed in the vicinity of the seating point of the passenger, preferably aft thereof, to assure that the front portion of the seating surface acts as a lever promoting the uprighting of the seat part from its lowest position.
In this arrangement the tilt axis can be disposed in a range of 30 to 70% of the depth of the seating surface.
In one advantageous aspect the seat contains a foamed cushion more particularly of soft PU foam material. Expediently the foamed cushion is removable and thus defined replaceable in the seat part.
To reduce the rise of the front portion of the seating surface when the seat part is tilted backwards, the seat and/or the foamed cushion may contain in the front portion a forwards downswept outer contour so that on tilting the seat part, only a very slight rise occurs in the front portion of the seating surface.
In one advantageous further embodiment the seat and/or the foamed cushion contains an outer contour, starting at the tilt axis which is initially upswept and then downswept forwards.
In accordance with another advantageous aspect the foamed cushion may contain in the front portion of the seating surface a lower Shore hardness than in the rear portion of the seating surface.
In this configuration, for example, a foam material having a lower Shore hardness may be provided in the front portion.
In an alternative aspect the foamed cushion is nicked in the front portion to reduce the Shore hardness, as may be achieved, for example, by a plurality of nicks oriented crosswise.
In another advantageous aspect the seating surface contains a front part hinged to the rear part of the seating surface and advanced on a slide guide.
In yet another advantageous aspect an upholster element is provided in the front portion of the seating surface. The volume of the upholster element is variable so that the passenger automatically varies the volume.
Advantageously the seat part has a positioner for changing the seating position.
In this configuration the positioner has at least one lifting device hinged at one end to the mounting frame and at the other to the seat part, more particularly in the region of the main pressure point of the passenger.
The lifting device contains at least two interhinged hinge members connected at one end to the seat part and at the other to the mounting frame, and an actuator engages a connecting point of the hinge members. In a normal position of the seat part the two hinge members are located at an angle to each other, as a result of which the resulting loads are transmitted substantially lossless to the mounting frame while the actuator is practically zero-loaded. In addition, the actuator is loaded in the correct direction when stressed.
In this configuration a pneumatic, hydraulic or electrical actuator may be put to use.
In accordance with another advantageous embodiment the actuator is hinged at one end to a front mounting bracket of the mounting frame and at the other to the connecting point of the hinge members.
In still another advantageous aspect a fold-down table is provided in the region of the backrest. The table held by two supporting arms spaced away from each other is swivel-mounted on the tilt axis of the seat part so that in the fold-down position the table is not included in the adjusting movement of the seat part, there also being no relative movement between the seat part and the table in the folded-up position.
Preferably at least one of the supporting arms of the table has a supporting element which is supported in the fold-down position of the table on the mounting frame.
In this configuration the supporting element may contain a peg engaging an assigned recess in the mounting frame.
Advantageously the seat part is configured as a one-part plastics seat shell.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an aircraft passenger seat, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.